胃癌術後に広範な胸膜化進展で再発した1例  [in Japanese] A Case of Postoperative Recurrence of Gastric Cancer with Diffuse Metastasis Around the Entire Subpleural Layer  [in Japanese]

背景.悪性胸水はしばしば悪性腫瘍発見の契機になるが,悪性胸水の診断は時に胸水細胞診や経皮的胸膜生検で得られず難渋することがある.症例.76歳男性.3年前に胃癌stage IBに対する幽門側胃切除の既往があった.微熱を主訴に近医受診し,右胸水を指摘され,当科入院となった.胸腔穿刺を施行し,ADA正常,CEA高値を示す滲出性胸水が得られたが,細胞診はclass 1であった.胸部CTでは右肺の臓側胸膜および壁側胸膜全周性の不整な肥厚と縦隔リンパ節腫大を認め,FDG-PETでは同部位に集積を認め,他臓器の異常集積は認めなかった.経皮的胸膜生検でも診断がつかず,胸腔鏡下胸膜生検を施行した.内腔は明らかな腫瘤を認めなかったが,壁側胸膜の生検ですべての検体から腺癌を認めた.胃癌切除の病理組織標本と比較し,胃癌の再発と診断した.結論.胃癌術後再発としての全周性の胸膜下進展はまれであり,報告する.

Background. Malignant pleural effusion (MPE) is often the first finding in the diagnosis of pleural malignancies, but obtaining a diagnosis of MPE can be difficult due to false-negative findings of pleural effusion cytology and percutaneous pleural biopsy. Case. A 76-year-old man with a history of pyloric gastrectomy for stage IB gastric cancer 3 years previously visited a local clinic with a low-grade fever. Right-sided pleural effusion was obtained on a chest X-ray film, and he was admitted to our hospital. We performed thoracentesis and obtained exudative pleural effusion, which showed a normal adenosine deaminase level and an elevated carcinoembryonic antigen level, but cytologically it was class 1. Chest computed tomography showed irregular thickening of the right visceral and parietal pleura and enlarged mediastinal lymph nodes. Fluorine 18-fluorodeoxyglucose-positron emission tomography revealed abnormal accumulation in the above sites without accumulation in any other organs. Because percutaneous pleural biopsy did not yield a definitive diagnosis, thoracoscopic pleural biopsy was performed. No obvious tumor was observed, but adenocarcinoma was detected pathologically in all the biopsy specimens obtained from the parietal pleura, and a diagnosis of gastric cancer recurrence was made. Conclusion. Diffuse subpleural metastasis can be a rare form of gastric cancer recurrence.